Selection on age of female reproduction in the marula fruit fly, Ceratitis cosyra (Walker) (Diptera: Tephritidae), decreases total antioxidant capacity and lipid peroxidation.

The oxidative damage caused to cells by Reactive Oxygen Species (ROS) is one of several factors implicated in causing ageing. Oxidative damage may also be a proximate cost of reproductive effort that mediates the trade-off often observed between reproduction and survival. However, how the balance between oxidative damage and antioxidant protection affects life-history strategies is not fully understood. To improve our understanding, we selected on female reproductive age in the marula fruit fly, Ceratitis cosyra, and quantified the impact of selection on female and male mortality risk, female fecundity, male sperm transfer, calling and mating. Against expectations, upward-selected lines lived shorter lives and experienced some reductions in reproductive performance. Selection affected oxidative damage to lipids and total antioxidant protection, but not in the direction predicted; longer lives were associated with elevated oxidative damage, arguing against the idea that accumulated oxidative damage reduces lifespan. Greater reproductive effort was also associated with elevated oxidative damage, suggesting that oxidative damage may be a cost of reproduction, although one that did not affect survival. Our results add to a body of data showing that the relationship between lifespan, reproduction and oxidative damage is more complex than predicted by existing theories.

Physico-chemical characteristics and functional properties of chitin and chitosan produced by Mucor circinelloides using yam bean as substrate.

Microbiological processes were used for chitin and chitosan production by Mucor circinelloides (UCP 050) grown in yam bean (Pachyrhizus erosus L. Urban) medium. The polysaccharides were extracted by alkali-acid treatment and structural investigations by X-ray diffraction, Fourier transform IR analysis, viscosity and thermal analysis by TG, DTG, and DTA were done. The highest biomass yield (20.7 g/L) was obtained at 96 hours. The highest levels of chitosan (64 mg/g) and chitin (500 mg/g) were produced at 48 and 72 hours, respectively. It was demonstrated that yam bean shows great potential as an economic medium and it is possible to achieve a good yield of chitosan with chemical properties that enable its use in biotechnological applications.

Use of trilostane for the treatment of pituitary-dependent hyperadrenocorticism in a cat.

Hyperadrenocorticism occurs much less frequently in cats than in dogs and, at present, is more difficult to manage successfully. This report documents the use of the steroid synthesis inhibitor trilostane for the treatment of hyperadrenocorticism in a domestic shorthaired cat with pituitary-dependent disease. Although trilostane was able to alleviate the severity of the clinical signs and was well tolerated, the cat subsequently died of renal failure secondary to a fungal infection of the urinary tract.

Pericardial effusion and cardiac tamponade secondary to brodifacoum toxicosis in a dog.

Hemorrhage resulting from ingestion of anticoagulant rodenticides may be evident at any traumatized site or in any body cavity. It is important for clinicians to include coagulopathies among the differential diagnoses for pericardial effusion and to evaluate clotting function before routine pericardiocentesis is performed.

Assessing insulin sensitivity in the cat: evaluation of the hyperinsulinemic euglycemic clamp and the minimal model analysis.

Current methods of assessing glucose tolerance in the cat are inadequate for quantifying insulin sensitivity. The hyperinsulinemic euglycemic clamp (EGC) and the minimal model analysis (MMA) of the frequently sampled intravenous glucose tolerance test (FSIGT) have been used in other species to assess the effects of insulin on glucose homeostasis. Each of these procedures was performed on healthy cats, two weeks apart, to generate indices of insulin sensitivity - M/I (amount of glucose metabolised per unit of plasma insulin concentration) from the EGC and S(I) (insulin sensitivity) from the MMA. Close and significant correlation between M/I and S(I) in individual cats was found (r=0.91, P=0.032). Use of these research methods may further our understanding of feline diabetes mellitus and other endocrinopathies.

Detection of orange juice adulteration with beet medium invert sugar using anion-exchange liquid chromatography with pulsed amperometric detection.

Carbohydrate analysis of 5 beet medium invert sugar (BMIS) samples and 10 pure orange juices was carried out using anion-exchange chromatography with a pulsed amperometric detector. This analysis revealed the presence of several oligosaccharides in BMIS that were in either low concentration or nonexistent in the orange juice samples. These oligosaccharides may be naturally present in sugar beets or synthesized during the acid and/or enzyme catalyzed hydrolysis of sucrose during the production of BMIS. BMIS was intentionally added to pure orange juice at levels of 5, 10, 15, and 20%. Subsequent liquid chromatographic (LC) analysis of these intentionally adulterated samples revealed that detection of 5% BMIS in orange juice was possible.